Top quark production is observed in pbarp collisions at sqrt s =
1.8 TeV at the Fermilab Tevatron.  The Collider Detector at Fermilab (CDF) and
D0 observe signals consistent with ttbar to WWbb-bar, but inconsistent with
the background predictions by 4.8 sigma (CDF), 4.6 sigma (D0).  Additional
evidence for the top quark is provided by a peak in the reconstructed mass
distribution.  The kinematic properties of the excess events are consistent
with the top quark decay.  They measure the top quark mass to be 176 +\- 8
(stat.) +\- (sys.) GeV/c^2 (CDF), 199^+19_ -21 (stat.) +\- 22 (sys.) GeV/c^2
(D0), and the ttbar production cross section to be 6.8^+3.6_ -2.4 pb (CDF),
6.4 +\- 2.2 pb (D0).